An incubator includes a rotating incubator rotor. The incubator rotor is provided with a plurality of element chambers which are arranged along the outer periphery of the incubator rotor and each of which accommodates a dry analysis element spotted with a sample and incubates the dry analysis element. A light measuring system has a light measuring head which measures the optical density of the dry analysis element. The light measuring system is provided with a correction system which compensates for fluctuation in the value of the optical density of the dry analysis element in each of the element chambers as measured by the light measuring head generated due to fluctuation in the distance between the light measuring head and the element chamber on the basis of a correction value which has been stored in the correction system element chamber by element chamber.
1. An incubator comprising a rotating incubator rotor provided with a plurality of element chambers which are arranged along the outer periphery of the incubator rotor and each of which accommodates a dry analysis element spotted with a sample and incubates the dry analysis element, wherein the improvement comprises that
the incubator rotor is provided with a cone-like slant surface which is formed below the element chambers and tapers downward toward the axis of rotation of the incubator rotor, a cylindrical rotating shaft which is connected to the lower end of the slant surface and an inner space of which opens to the space defined by the cone-like slant surface so that the dry analysis element in each element chamber can be discarded outside the incubator through a space defined by the cone-like slant surface and the inner space of the cylindrical rotating shaft, and a bearing member which supports the cylindrical rotating shaft for rotation about the axis of rotation of the incubator rotor.
2. An incubator as defined in claim 1 in which the slant surface is at an angle not smaller than 30° to the horizontal.